The present invention relates generally to motive power and fluid driving systems, and particularly to a method of controlling these motive power and fluid driving systems.
In the above-identified parent case, a method and system were taught for increasing the operating efficiency of natural gas compressor and engine units. According to this method, the energy required to compress the natural gas was related to the energy consumed by the engine to determine the most efficient operation of the natural gas compressor and the engine as a unit. This energy relationship was expressed as an "energy quotient," and was employed as the basis of controlling the operation of the natural gas compressor and engine unit.
Under the above method, one or more of the control parameters (i.e., the compressor loading and/or the engine speed) are adjusted to substantially maximize the energy quotient for the unit. Since the individual energy efficiencies of the gas compressor and the engine driving the gas compressor are not addressed, it is possible for an adjustment of the control parameters to adversely affect the individual energy efficiency of the gas compressor or the engine. However, such an adjustment would nevertheless increase the combined efficiencies of the gas compressor and the engine as a unit. Thus, for example, while a manufacturer's specification may indicate a decrease in efficiency for the engine where the speed is decreased below some rated value, a decrease in the engine speed may achieve an increase in the combined efficiency of the gas compressor and the engine.
While the above method has been found particularly advantageous for natural gas engine driven compressors, it is believed that the principles of this method may also find application in other motive power and fluid driving systems. Thus, the control method may be utilized in systems which transfer or impart a driving force to fluids in addition to gas, such a variety of liquids with viscosities from water to molasses, or a combination of liquid and gas. Similarly, the control method may be utilized in systems employing motive power means other than engines for driving the compressor or other fluid driving means, such as an electrically powered motor.
Accordingly, it is a principle object of the present invention to provide a method of controlling a motive power and fluid driving system which substantially maximizes the energy efficiency of the system.
It is a more specific object of the present invention to provide a method of controlling a motive power and fluid driving system which substantially maximizes an energy quotient for the motive power and fluid driving system.
It is an additional object of the present invention to provide a motive power and fluid driving system which substantially maximizes the energy quotient for the motive power and fluid driving system at a predetermined capacity of fluid flow.
To achieve the foregoing objects, the present invention provides for a method of controlling a motive power and fluid driving system which includes the steps of sensing a plurality of operating parameters and at least one control parameter defining an energy quotient for the motive power and fluid driving system, and adjusting the control parameter to substantially maximize this energy quotient.
Additional advantages and features of the present invention will become apparent from a reading of the detailed description of the preferred embodiments which makes reference to the following set of drawings in which: